The present invention relates to a printing device used independently, or as a terminal device connected to a computer etc., specifically to a printing device that does not require a commercial power supply or a charged battery as a power source.
It has been common practice to utilize electric energy provided externally as a power source in a printing device. For example, printing devices have been used as a stationary printer utilizing the commercial power supplied to a power source outlet, or as a mobile printer utilizing a charger so as to charge a built-in battery from the commercial power source. Mobile computers that are capable of continuous usage in locations, where for example a commercial power is not available, have been available. This technology is described, for instance, in Japanese Patent Application Publication No. 4-340118. However, no related art is available for a printing device.
The age of mobile computing has arrived and the demand for printing, away in the field or a remote site, has increased. However, with the above-mentioned printing devices, printing needs had to be given up, if there is no power source outlet that enables to utilize the commercial power source available at the destination, or if the supply of spare batteries is in short.